Scaling and Security in Parallel: A Comprehensive Analysis of the 12 EIPs in the Ethereum Fusaka Upgrade

Author: @ChromiteMerge

Ethereum is set to undergo a hard fork upgrade named "Fusaka" on December 3, 2025. This upgrade includes a total of 12 Ethereum Improvement Proposals (EIPs), which function like 12 precise components that will collectively enhance Ethereum's scalability, security, and operational efficiency. Below, the author categorizes these 12 EIPs and explains in simple terms what problems they solve and why they are crucial for the future of Ethereum.

Scalability! Making Ethereum Faster and More Capable

This is the core theme of the Fusaka upgrade. To support the global digital economy, Ethereum must address issues of transaction congestion and high fees. The following EIPs are specifically aimed at achieving this goal, particularly around reducing costs and increasing efficiency for Layer 2 scalability.

EIP-7594: PeerDAS - Data Availability Sampling

Pain Point: Since the Dencun upgrade introduced data "Blobs" for affordable data storage on Layer 2, a core issue has arisen: how to ensure the vast amounts of data are genuinely available? Currently, the approach requires each validating node to download and verify all blob data contained in a block. This method is feasible when a block carries a maximum of 9 Blobs. However, if the number of Blobs increases further in the future (for example, to 128), downloading and verifying all blobs will incur high costs, raising the participation threshold for validating nodes and threatening the network's decentralization.

Solution: PeerDAS (Peer Data Availability Sampling) transforms the traditional "full check" into "sampling checks". In simple terms:

1. The network slices the complete blob data.
2. Each validator does not need to download all blobs, only needs to randomly download and check a few data fragments.
3. Then, by mutually checking and exchanging verification results, they can collectively confirm the integrity and availability of the entire blob data set.

It's like a large jigsaw puzzle where everyone has only a few pieces, but as long as they verify the key connections with each other, they can confirm the whole puzzle is intact. It is worth noting that PeerDAS is not a brand-new invention; the core DAS concept has been successfully implemented in third-party DA projects like Celestia. The implementation of PeerDAS is more like filling a critical "technical debt" in Ethereum's long-term scalability blueprint.

Significance: PeerDAS significantly reduces the storage burden on validators, clearing potential obstacles that could weaken decentralization for large-scale data expansion in Ethereum. In the future, each block is expected to accommodate hundreds of Blobs, supporting the Teragas vision claiming up to 10 million TPS, while ordinary users can easily run validators, maintaining the network's decentralization.

EIP-7892: BPO Hard Fork - Lightweight Parameter Upgrade

Pain Point: The market's demand for Layer 2 data capacity changes rapidly; if every adjustment to the maximum number of Blobs requires waiting for a large upgrade like Fusaka, it would be too slow and unable to keep pace with the ecosystem's development.

Solution: This EIP defines a special "Blob Parameter Only Hardfork" (BPO) mechanism. This upgrade is very lightweight; it only modifies a few parameters related to Blobs (such as the target number of Blobs per block) and does not involve complex code changes. Node operators do not even need to upgrade client software; they just need to accept new parameters at a specified time, as simple as updating a configuration file online.

Significance: The BPO mechanism gives Ethereum the ability to quickly and safely adjust network capacity. For example, after this Fusaka upgrade, the community plans to execute two consecutive BPO upgrades in a short period, gradually doubling the Blob capacity. This allows Ethereum to expand blob space on demand, flexibly, and progressively, enabling smoother increases in L2 costs and throughput while keeping risks more manageable.

EIP-7918: Stabilizing Blob Fee Market

Pain Point: The previous mechanism for adjusting Blob fees was too "market-driven," leading to some unexpected issues. First, when market demand for Blobs is low, fees drop to near zero, which does not effectively stimulate new demand and instead creates an abnormal "historical low price." Conversely, when demand is high, blob fees soar, creating another extreme high price. This dramatic price "internal competition" makes fee planning for Layer 2 difficult.

Solution: The core idea of EIP-7918 is to prevent Blob fees from fluctuating without limits and instead set a reasonable price range, i.e., a flexible "minimum consumption." The implementation links the upper and lower limits of blob fees to the execution fees of Layer 2 on Layer 1. Whether updating the state root or verifying a ZK proof, these execution fees are relatively stable and not significantly related to the transaction volume within L2 blocks. Therefore, linking the upper and lower limits of blob fees to this stable "anchor" can prevent their prices from wildly fluctuating.

Significance: The direct benefit of this improvement is to prevent "internal competition" in the Blob fee market, making the operating cost model for Layer 2 projects more predictable. This way, Layer 2 can set more stable and reasonable transaction fees for end users, avoiding the "free today, sky-high tomorrow" rollercoaster experience.

EIP-7935: Enhancing Mainnet Transaction Capacity

Pain Point: The total number of transactions that each Ethereum block can accommodate is determined by the "block gas limit" (currently about 30 million) and has not been adjusted for years. To increase the overall throughput of the network, the most direct way is to raise this limit, but it must ensure not to raise the hardware threshold for validating nodes or weaken decentralization.

Solution: This proposal suggests raising the default gas limit for blocks to a new level (specific value TBD, possibly 45 million or higher). This is not a mandatory lock but rather a new recommended default value to guide consensus layer validators to gradually accept a higher gas limit.

Significance: This means that each Layer 1 block can package more transactions, directly boosting the TPS of the Ethereum mainnet and alleviating network congestion and soaring gas fees. Of course, this also places higher demands on the hardware of validators, so the community will proceed with testing and advancement cautiously.

Security and Stability! Building a Strong Defense for the Network

While expanding capacity, it is essential to ensure the security and stability of the network. The Ethereum Foundation launched the "Trillion Dollar Security (1TS)" initiative in May 2025, aiming to establish an Ethereum network capable of securely supporting trillion-dollar-level assets. Several EIPs in Fusaka are advancing the 1TS plan, akin to installing more reliable "brakes" and "guardrails" on the fast-moving Ethereum.

EIP-7934: Setting a Physical Block Size Limit

Pain Point: Ethereum's "block gas limit" only concerns the total computational load of all transactions within a block but does not specify the physical size of the block. This creates a vulnerability: attackers can carefully construct a large number of "low-cost, high-volume" transactions (for example, transferring 0 ETH to many addresses, which has a very low computational load but a large data volume), thus packaging a block that does not exceed the computational limit but has an unusually large physical size. Such "data bomb" blocks would propagate slowly through the network, potentially causing some nodes to miss data and fall behind, posing a serious DoS (Denial of Service) attack risk.

Solution: Set a hard limit of 10MB for the size of each block. Any block exceeding this size will be rejected by the network.

Significance: This is akin to setting a maximum size for trucks on the highway to prevent "oversized" vehicles from affecting traffic. It ensures that blocks can propagate quickly through the network, reducing latency and enhancing the network's stability and resistance to attacks.

EIP-7825: Setting a Gas Limit for Individual Transactions

Pain Point: Currently, while blocks have a total gas limit, individual transactions do not. In theory, someone could construct a transaction that consumes nearly all the resources of a block, pushing out all other transactions, which is both unfair and poses security risks.

Solution: Set a hard limit of 16.77 million gas for each transaction. Complex operations exceeding this scale need to be split into multiple transactions before submission.

Significance: This enhances the fairness and predictability of the network, ensuring that no single transaction can "monopolize" the block. Ordinary user transactions will not be excessively delayed due to a "super large order."

EIP-7823 & EIP-7883: Strengthening ModExp Precompilation Security

Pain Point: ModExp is a function used in Ethereum for handling large number modular exponentiation, commonly found in some cryptographic applications. However, it poses two risks: first, there is no limit on the length of input numbers, which could be exploited by maliciously constructed oversized inputs; second, its gas fee standard is relatively low, allowing attackers to call it in large quantities at a low cost, consuming node resources.

Solution:

• EIP-7823: Set an upper limit of 8192 bits for the input length of ModExp, which is more than sufficient for practical application needs.
• EIP-7883: Increase the gas fees for ModExp, especially for larger inputs, where costs will rise sharply to ensure that computational costs align with resource consumption.

Significance: These two improvements work in tandem to eliminate a potential attack vector. They are like setting a "maximum workload" for a computing service while adjusting the "tiered pricing" to prevent abuse, thereby enhancing the overall robustness of the network.

Functional Upgrades! Providing Developers with More Powerful Tools

In addition to scalability and security, Fusaka also brings some practical new tools and features for developers, making it more efficient and powerful to build applications on Ethereum.

EIP-7951: Compatibility with Mainstream Hardware Signatures

Pain Point: The security chips built into everyday devices such as smartphones (like iPhones), bank USB keys, and hardware security modules commonly use a cryptographic standard called secp256r1 (also known as P-256). However, Ethereum defaults to another standard, secp256k1, which prevents these mainstream devices from directly interacting securely with Ethereum, limiting the widespread adoption of Web3.

Solution: Introduce a new precompiled contract that allows Ethereum to natively support and verify signatures from the secp256r1 curve.

Significance: This is a milestone improvement. It opens the door for Ethereum to connect with billions of hardware devices globally. In the future, you can directly use the security chip in your smartphone to sign Ethereum transactions without needing additional wallet applications or complex conversions, resulting in a smoother experience with higher security. This significantly lowers the barrier for the traditional world to access Ethereum, marking a major benefit for the integration of Web2 and Web3.

EIP-7939: Adding CLZ Efficient Calculation Instruction

Pain Point: In smart contracts and cryptographic applications, it is often necessary to calculate how many consecutive zero bits are at the beginning of a 256-bit number (for example, in hashing algorithms, compression algorithms, zero-knowledge proofs, etc.). Currently, there is no direct Opcode in the Ethereum EVM to support this operation, forcing developers to use complex Solidity code, which is costly and inefficient.

Solution: Introduce a new Opcode in the EVM called "CLZ" (Count Leading Zeros) to complete the calculation in one step.

Significance: This provides developers with a time-saving and labor-saving professional tool. It can significantly reduce the gas costs of related calculations, allowing applications that rely on complex mathematical computations (especially ZK Rollups) to run cheaper and more efficiently.

Network Optimization! Invisible Improvements for a Healthier Ecosystem

The last two EIPs may not be strongly perceived by users, but they are crucial for the long-term healthy operation and coordination efficiency of the network.

EIP-7642: Reducing the Synchronization Burden for New Nodes

Pain Point: Over time, Ethereum has accumulated a vast amount of historical data. A new node joining the network needs to download and synchronize all this data, which is time-consuming and labor-intensive, raising the entry threshold. Additionally, since Ethereum transitioned to PoS consensus after The Merge, some unnecessary fields remain in the old transaction receipt information, causing redundancy.

Solution: Introduce a "data expiration" strategy, allowing new nodes to skip certain outdated data during synchronization; simultaneously, simplify the format of transaction receipts by removing unnecessary redundant fields. This way, new nodes can save a lot of useless data when synchronizing from the genesis block.

Significance: This improvement "slims down" node operations, potentially reducing data transmission by about 530GB for each full node synchronization! A lower threshold means more people can run nodes, enhancing the network's decentralization and robustness.

EIP-7917: Deterministic Block Order and Pre-confirmation

Pain Point: To understand the importance of this EIP, we must first discuss a core pain point of current Layer 2 Rollups: centralized sequencers. Currently, most Rollups rely on a single entity to receive and sort user L2 transactions, granting it the power to censor transactions and extract MEV, which contradicts the spirit of decentralization. To address this issue, the community proposed the concept of Based Rollup—simply abandoning the L2 sequencer and directly using Ethereum L1's block proposer to sort L2 transactions, thereby inheriting L1's decentralization and neutrality.

However, this solution has a fatal flaw: slowness. Layer 2 must wait for L1 blocks to be on-chain before executing transactions, resulting in significant delays and poor user experience. The only solution is to introduce a "pre-confirmation" mechanism, where the L2 gateway can obtain commitments in advance from future L1 proposers: "I guarantee that I will package the transactions you submit on-chain, or I will compensate you," allowing Layer 2 to update its state (such as account balances) in advance to reduce user waiting time. But under the current random proposer selection mechanism, the gateway has no idea who to "negotiate" with, making reliable pre-confirmation impossible.

Solution: EIP-7917 modifies the consensus protocol so that the proposer order for a future period can be calculated deterministically and made public. It transforms "on-the-spot drawing" into a publicly accessible, pre-arranged "block schedule."

Significance: This improvement is a key cornerstone for realizing next-generation decentralized solutions like Based Rollup. With this "schedule," L2 gateways can identify future proposers for specific blocks in advance and negotiate directly with them to obtain a trustworthy pre-confirmation guaranteed by slash penalties. This allows Based Rollup to enjoy L1-level decentralization and security while providing users with an instant transaction experience close to that of centralized sequencers. It can be said that EIP-7917 opens a crucial door for Ethereum's ecosystem to achieve deeper levels of "decentralized" scalability.

Why is the Fusaka Upgrade Timely?

The Fusaka upgrade is not just a technical iteration; it is also an important strategic upgrade for Ethereum in the context of traditional finance's large-scale on-chain integration of RWA and stablecoins. Currently, Ethereum serves as the main battlefield, hosting over 56% of the total stablecoin supply in the network, becoming the core settlement layer of the global digital dollar economy. The goal of Fusaka is to prepare for the influx of "Wall Street" level assets and transaction volumes.

• Custom Layer 2 Chains for Institutional Needs, Providing Unlimited Scalability "Fuel"

With the entry of traditional financial institutions, we will see an increasing number of Layer 2 "dedicated chains" tailored for specific needs (such as KYC compliance). These dedicated chains require the Ethereum mainnet to provide vast, affordable, and secure data storage space (i.e., Data Availability).

EIPs like EIP-7594, EIP-7892, and EIP-7918 in Fusaka are designed to meet this demand. Their core objective is singular: to significantly reduce the cost of data publishing for Layer 2 and provide flexible scalability on demand.

In fact, after the Pectra upgrade, blob fees are already very low; why continue to lower them? Because Fusaka adopts a strategy of "sacrificing short-term fee income for larger-scale economic activity," aiming to grow the entire network's GDP, allowing more transactions to convert into more staking and ETH burns, thereby supporting the overall value of the network.

• Moving Towards "Trillion Dollar Security," Building an Unbreakable Financial Infrastructure

For financial institutions managing trillions in assets, security is an inviolable bottom line. The Ethereum community has also proposed the ambitious goal of "trillion-dollar security." EIPs like EIP-7934, EIP-7825, EIP-7823, and EIP-7883 are aimed at reinforcing the walls and eliminating potential security risks, advancing towards this goal.

In summary, the main line of the Fusaka upgrade is clear and firm: scalability and security. Driven by favorable regulations and market enthusiasm, the Fusaka upgrade is indeed timely. It will help Ethereum seize the policy tailwind, solidify its dominant position in the stablecoin and asset on-chain space, and further transform Ethereum from a "speculative asset" into a mainstream financial infrastructure.

Conclusion: Deep Changes Beneath the Surface

As an important upgrade at the end of 2025, Fusaka quietly injects powerful internal momentum into Ethereum without overwhelming market hype. The 12 improvements it encompasses directly address the three major pain points of scalability, security, and efficiency. What it does is broaden Ethereum's "value highway," enhancing its capacity and reliability to prepare for the future influx of users, assets, and applications.

For ordinary users, these changes may seem "quiet," but their impact will be profound. A more powerful, efficient, and secure Ethereum will have the ability to realize grand visions that were previously only imaginable—whether it's a global instant settlement network or "on-chain Wall Street." Fusaka is a solid step towards this future.

• This article is based on publicly available information and does not constitute investment advice. Cryptocurrency investments carry significant risks; please make cautious decisions and DYOR.

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